1. 5/15/2015BAE2023 Physical Properties of Biological Materials Lecture 5 1 Quick Review –Describe size, shape, style –Sphericity –Determining volume, equipment –Surface area –Electronic method for estimation Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48

2. 5/15/2015BAE2023 Physical Properties of Biological Materials Lecture 5 2 –Density: Definition: weight per unit volume Liquid density determined by pycnometer, hydrometer Common liquid food product in Table B.1 in Appendix B May change significantly with temperature –Specific Gravity: Definition: ratio of density of liquid to density of water Change due to temperature is small Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48

3. 5/15/2015BAE2023 Physical Properties of Biological Materials Lecture 5 3 Hydrometer –Brix: sucrose –Lactometers: milk density –Oleometers: veg. oil

4. 5/15/2015BAE2023 Physical Properties of Biological Materials Lecture 5 4 –Foams: products with large amounts of air incorporated during processing Whipped cream, sherbet, ice cream Describe using “overrun”: % increase in volume attributed to air Icemilk: 30-40% Sherbet: 50-80% Cream: 100-120% Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48

5. 5/15/2015BAE2023 Physical Properties of Biological Materials Lecture 5 5 –Particulate Materials Solid Density: weight per unit volume excluding interior pores Particle Density: weight per unit volume of individual kernel Bulk Density: weight per total volume occupied by large quantity of kernels –Density of water is different than other components…we can distinguish solid density and water density Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48

6. 5/15/2015BAE2023 Physical Properties of Biological Materials Lecture 5 6 For water and solids: BOOK CORRECTION ex. 2.4 Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48

7. 5/15/2015BAE2023 Physical Properties of Biological Materials Lecture 5 7 –“particle density is highly dependent on moisture content” EX: suppose the soybean moisture content were 0.16 and the kernel density were 1.232 g/cm 3 Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48

8. 5/15/2015BAE2023 Physical Properties of Biological Materials Lecture 5 8 –Density of fruits and vegetables: Determined by water displacement method. Example 2.5 Table Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48

9. 5/15/2015BAE2023 Physical Properties of Biological Materials Lecture 5 9

10. 5/15/2015BAE2023 Physical Properties of Biological Materials Lecture 5 10 –Bulk density Determined by pouring a sample into a container with known dimensions. Variables: method of filling and striking surface Conversion: 1 bushel = 1.244 ft^3 or 0.035239 m^3 Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48

11. 5/15/2015BAE2023 Physical Properties of Biological Materials Lecture 5 11 –Test Weight Factors affecting test weight…moisture content, broken kernels, fines, variety/hybrid, growing conditions –Bulk density Table 2.3 (you will need this table later on!!!) –Porosity: space between particles, not within particles Calculated from bulk density and particle density Example 2.6 Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48

12. 5/15/2015BAE2023 Physical Properties of Biological Materials Lecture 5 12 –Regression and Statistical Distribution Equation 2.6 What is this business about logs? Mean and standard deviation (measure of variability) r^2 Normal distribution Influences how we design equipment to handle particles Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48

13. 5/15/2015BAE2023 Physical Properties of Biological Materials Lecture 5 13 –Sieve analysis –Sized by the 64 th Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48

14. 5/15/2015BAE2023 Physical Properties of Biological Materials Lecture 5 14 –Radius of Curvature Sharpness of curvature will determine how readily an object will roll Determined by radius of curvature Figure 2.6 Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48

15. 5/15/2015BAE2023 Physical Properties of Biological Materials Lecture 5 15 –Applications Separate foreign material Proper singulation during planting Separate germs, pericarps, hulls from endosperm or cotyledon Size grades and shape Density separation (milk separator) Watermelon sorting by shape and weight Sorting by shape…orientation is a problem Optical sorting Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48

16. 5/15/201516 HW#4 Part 2 Assignment Due 1/31 Problem 1: –A) Calculate the sphericity of a blueberry, a Red Haven peach, and a Norchip potato. –B) Which one is more spherical? Problem 2: –Calculate the volume of a Bart 46 Wheat kernel Reference class handout –What is the percentage error when compared to the volume determined by testing? Problem 3: –Using a piece of fruit or vegetable of your choice, and example 2.3 in Chpt 2, determine the volume and surface area. BAE2023 Physical Properties of Biological Materials Lecture 5

17. 5/15/201517 HW#4 Part 2 Assignment Due 1/31 Problem 4: #2.6 in book Problem 5: #2.10 in book BAE2023 Physical Properties of Biological Materials Lecture 5